A novel linear epitope at the C-terminal region of the classical swine fever virus E2 protein elicits neutralizing activity.

Abstract

Classical swine fever virus (CSFV) is a member of the genus Pestivirus, which causes serious economic losses. The re-emergence of the disease in Japan in 2018 has increased awareness of CSFV. In this study, Balb/c mice were immunized with plant-derived E2 protein, and four monoclonal antibodies (mAbs) 4B11, 7B3, 11A5 and 6F3 were generated. Two of these mAbs, 4B11 and 7B3, effectively blocked CSFV infection of PK-15 cells. Both mAbs recognized a novel linear epitope, 256CLIGNTTVKVHASDER271. The neutralizing ability of anti-CSFV serum decreased 63%, when pre-incubated with the linear peptide at 200 μg/mL. Structural analysis showed that this linear epitope is present at the border of Domain C and Domain D on the surface of the E2 protein. Alignment of amino acid sequences showed that the epitope was conserved in different subgroups of CSFV but not in other members of the Pestivirus genus. Consistently with the analysis above, this epitope distinguished antibodies against CSFV from those against bovine viral diarrhea virus (BVDV). Our study provides an ideal candidate peptide for new vaccine design and differential diagnosis of CSFV. These findings will contribute to the control and eradication of classical swine fever.

• Authors: Qianru Xu, Junqing Guo, Fanshu Ma, Linke Liu, Yanan Wang, Shenli Zhang, Xiangxiang Niu, Xueyang Li, Min Jiang, Yanwei Wang, Li Wang, Yunchao Liu, Qingmei Li, Shujun Chai, Ruining Wang, Qiang Ma, Erqin Zhang, Gaiping Zhang
• Journal: International journal of biological macromolecules (Int J Biol Macromol) Vol. 189 Pg. 837-846 (Oct 31 2021) ISSN: 1879-0003 [Electronic] Netherlands
• PMID: 34403672 (Publication Type: Journal Article)
• Copyright: Copyright © 2021 Elsevier B.V. All rights reserved.

Chemical References

• Antibodies, Monoclonal
• Antibodies, Neutralizing
• Epitopes
• Peptide Library
• Viral Envelope Proteins
• glycoprotein E2, classical swine fever virus

Topics

• Amino Acid Sequence
• Animals
• Antibodies, Monoclonal (immunology)
• Antibodies, Neutralizing (immunology)
• Antibody Specificity (immunology)
• Classical Swine Fever Virus (chemistry, immunology)
• Conserved Sequence
• Epitopes (immunology)
• Female
• Mice, Inbred BALB C
• Models, Molecular
• Peptide Library
• Viral Envelope Proteins (chemistry, immunology)
• Mice